Retractable ball pen latching mechanism



Aug- 27, 1957 'I-l. w. SAMS l2,804,048

RETRACTABLE BALL PEN LATCHING MECHANISM Filed April 9, 1954.

ATTRNCY-S Unite assistita RETRACTABLE BALL PEN LATCHING MECHANISM Herbert W. Sams, Atlanta, Ga., assigner to Scripto, inc.,

. Atlanta, Ga., a corporation of Georgia This invention relates generally to retractable ball pens in which a ball point and reservoir unit is retractably arranged so that it may alternatively `be withdrawn within the barrel housing of the pen when not in use or projected therefrom for writing, and more particularly to an improved latch mechanism for controlling the projection and retraction of the ball point unit.

Briefly described, the latch mechanism of the present invention is characterized by an arrangement incorporating it with an operating plunger for insertion therewith forwardly within a barrel housing having an open rear end, the latch mechanism being made releasably engageable with the barrel housing at alternative positions corresponding to rearwardly projected and forwardly depressed positions of the plunger for retracting and projecting the ball point unit, and the latch mechanism also remaining releasable entirely from the barrel housing for removal of the plunger and ball point unit therefrom whenever desired, as when replacement of the ball point unit is necessary. i

The present invention is described in further detail below in connection with the accompanying drawings, in which:

Fig. l is a longitudinal section of a retractable ball pen incorporating a latch mechanism arranged according to the present invention, with the latch mechanism shown in rearwardly projected position for retraction of the ball point and reservoir unit connected therewith;

Fig. 2 is an enlarged fragmentary longitudinal section corresponding generally to Fig. l, but showing the latch mechanism in forwardly depressed position for projection of the ball point unit;

Fig. 3 is a transverse sectional detail taken substantially at the line 33 in Fig. 2;

Fig. 4 is a side elevation of the plunger and latch means carried thereby as seen from the right in Figs. l and 2;

housing 10 is arranged to contain slidably within the forward portion thereof a ball point and reservoir unit constituted by an ink reservoir tube 12 fitted at its forward end with a ball point element 14, with an operating plunger 16 connected at the rear end of the reservoir tube 12 and slidably disposed within the rear portion of the barrel housing 10 so that it projects from the rear open end thereof for operating manipulation.

Interiorly, the barrel housing is formed adjacent its forward end with an inwardly facing annular shoulder past which the ball point element 14 may be projected to an exterior writing position as shown in Fig. 2, but which otherwise contains the ball point and reservoir unit rearwardly within the barrel housing 11i. Above the annular shoulder 18 the barrel housing 10 is further formed interiorly with spaced longitudinal ribs 20 for laterally supporting the ink reservoir tube 16 so that it may be formed of a compressible plastic material as disclosed in copend Patented Ang., 27, 1957 ing application Serial No. 386,946, led October 19, 1953, now Patent No. 2,778,337.

The longitudinal ribs 20 are terminated intermediately of the length of barrel housing 1t) in order also to serve at their rear ends as bottoming shoulders for a compression spring 22 extending therefrom against the forward end of the plunger 16 and thereby providing means for biasing the plunger 16 rearwardly with respect to the barrel housing 10, Rearwardly beyond the longitudinal ribs 20, the barrel housing 10 is tubular in form for slidably receiving the plunger 16 within the rear open end thereof. The plunger 16 is in turn formed with a generally cylindrical cross section for slidable disposition within this rear tubular portion of the barrel housing 10, but has la longitudinal recess 24 extending at one side thereof between forward and rear end walls 26 and 28 spaced adjacent the respective plunger ends. The plunger 16 is further formed with a lateral shroud lug 30 at the rear end wall 28 of the recess 24 formed therein, and the forward plunger end has an extending clutch shank 32 formed thereat for frictionally fitting within the rear end of the ink tube reservoir 12 and thereby connecting the ball point and reservoir unit to move with the plunger 16.

Exteriorly of the barrel housing 10 a pocket clip 34 is Xed thereon by mounting ears 36 extended through clearance openings in the wall of the barrel housing 10 and crimped interiorly thereof to x the pocket clip 34 in place for use in the usual manner. This pocket clip 34 means carried by the plunger 16 as indicated generally by the reference numeral 40.

The latch means 40 is disposed in the longitudinal plunger recess 24 and is formed as a unitary spring strip comprising a latch arm portion 42 that is biased laterally outward from the recess 24, and that extends rearwardly from the forward recess end wall 26, past the abutment means formed by the pocket clip lip 34, to a lateral extension 44 thereon disposed beneath the plunger shroud lug 30 at the rear recess end wall 28. This latch arm portion 42 is further formed with rearwardly facing iirst and second latch notches 46 and 4S that provide corresponding shoulders spaced thereon in stepped relation forwardly from the lateral extension 44.

The barrel housing 10 is arranged with a rearwardly opening clearance slot 50 aligned with the abutment means 38 to allow projection of the lateral latch arm extension 44 therethrough when the irst latch notch 46 is engaged with the Vabutment means 38, and the second latch notch 48 is steeped outwardly beyond the first latch notch 46; both latch notches 46 and 48 being formed in pairs at the outwardly extending edges of opposite side ilanges 52 arranged intermediately along the latch arm portion 42, with each notch pair 46 and 48 being formed by stepped shoulders at the extending edges of flanges 52 that have only the rear shoulder faces disposed at a sufiicient angle with respect to the latch arm portion 42 for retaining engagement with the abutment means 38.

The latch means 46 further comprises a lateral base portion 54 joined at one side to the forward end of the latch arm portion 42, and at the other side to an opposed biasing leg portion 56 extending rearwardly therefrom in a length exceedingthe length of vthe plunger recess 24 sufficiently for bowed dispositionbetween the end walls 26 and 28 of the recess 24 so as to maintain the cess end wall 26 with the latch arm portion 42 biased outwardly from the recess 24. This disposition of the biasing leg portion 56 is particularly effective in maintaining the latch means 4t) properly and firmly disposed in the recess 24 of a plunger 16 formed of plastic material, such as might conveniently be used for forming both the plunger 16 and barrel housing 1h, but which material is characteristically subject to cold flow that often causes difficulty with shifting of supporting surfaces formed therein.

As a result of the above described arrangement of the latch means 4t?, the plunger 16 is insertable, together with a ball point and reservoir unit connected at its forward clutch shank 52, forwardly within the rear open end of the barrel housing 10 to be retained in operating relation with respect thereto. Upon insertion of the plunger 16 within the rear end of the barrel housing 1t), the latch means 40 operates to engage the abutment means formed by the pocket clip lip 3S iirst at the second latch notch pair 48, as illustrated in Fig. 1, and thereby retain the plunger 16, against the yieldable bias thereon from the compression spring 22, at a rearwardly projected position maintaining the ball point and reservoir unit connected thereto at a retracted disposition with respect to the barrel housing 10.

It should be noted in this connection that the lateral plunger shroud lug 30 has a lateral extent suiiicient to overlie completely the lateral latch arm extension 44 at this rearwardly projected position of the plunger 16, and thereby guard against accidental release of the latch means 4t). However, at this rearwardly projected position of the plunger 16, the lateral latch arm extension 44 is disposed beyond the rear end of the barrel housing 10 and may be intentionally pressed inwardly beneath the plunger shroud lug 349, whenever desired, to release the latch means 40 and allow removal of the plunger 16 from the barrel housing 10. A retaining band 16 is clinched on the plunger 16 over the recess 24 and just below the lateral latch arm extension 44 to retain the outwardly biased latch arm portion 42 when the latch means 40 is released in this way to remove the plunger 16 from the barrel housing 10.

With the plunger 16 at rearwardly projected position so that the ball point and reservoir unit connected thereto is retracted within the barrel housing 10, forward pressure on the plunger 16 results in moving it forwardly within the barrel housing 111 to a forwardly depressed position at which the iirst latch notch pair 46 will engage the abutment means 3S and retain the plunger 16 with the ball point and reservoir unit projected at the forward end of the barrel housing 10 to writing position, as illustrated in Fig. 2.

When this happens, the lateral latch arm extension 44 moves downwardly at the same time to a projecting disposition through the clearance slot in the barrel housing 1t), with the projection thereof being suiiicient to release the rst latch notch 46 from the abutment means 38 when the lateral extension 44 is manually pressed inward to the limit permitted by the plunger shroud lug 30 and the exterior surface of the barrel housing 1@ adjacent the clearance slot 50.

Because the second latch notch pair' 48 is stepped outwardly with respect to the rst latch notch pair 446, inwardly pressing the lateral latch arm extension 44 in the above noted manner results in releasing the latch arm portion 42 from engagement with the abutment means 38 at the rst latch notch pair 46 to alternative engagement at the second latch notch pair 48, and thereby allows return movement of the plunger 16 from forwardly depressed to rearwardly projected position, so as to retract the ball point and reservoir unit again within the barrel housing 1t); and at which rearwardly projected position the plunger 16 will be retained with respect to the barrel housing unless the lateral latch arm extension 44 is specially manipulated by pressing it further inward beneath the plunger shroud lug 3`0 as previously explained.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this descriptionfor otherwise except as defined in the appended claims.

I claim:

1. In a retractable ball pen, the combination comprising a barrel housing having a rear, open end, tubular portion, a plunger of a generally uniform cross section slidably disposed in said tubular portion for movement between rearwardly projected and forwardly depressed positions with respect to said barrel housing and being longitudinally recessed at one side thereof between forward and rear end walls that are spaced adjacent the respective plunger ends, forwardly facing abutment means extending into said tubular barrel portion and into said n longitudinal plunger recess to prevent rotation of said plunger, said plunger recess forward end wall and the remainder of said plunger extending forwardly therefrom being spaced from said barrel by an extent at least equal to the portion of said abutment means extending inwardly from said barrel to allow movement of the forward portion of said plunger past said abutment means, latch means arranged within said recess and incorporating a latch arm portion biased laterally outward from said recess and extending rearwardly from the recess forward end wall past said abutment means to a lateral extension thereon and formed with rearwardly facing first and second latch shoulders spaced thereon in outwardly stepped relation forwardly from said lateral extension, said rst and second latch shoulders being alternatively engageable with said abutment means, said latch means being manually accessible for a limited manual displacement to release said first latch shoulder from said abutment means by depression of said latch means inwardly to allow rearward movement of said plunger to projected position thereof While said second latch shoulder engages said abutment means, and said latch means being accessible for further inward displacement to release said second latch shoulder from said abutment means to a1- low said plunger to be removed from the open rear end of said barrel housing.

2. In a retractable ball pen, the combination defined in claim 1 and further characterized in that a pocket clip is lixed exteriorly on said barrel housing with a rear lateral lip portion thereof extending inwardly through a clearance opening in the wall of said barrel housing and forming said abutment means.

3. in a retractable ball pen, the combination defined in claim 1 and further characterized in that a lateral shroud lug is formed on said plunger and has a lateral extent suflicient to overlie said lateral latch arm extension when said second latch shoulder is engaged with said abutment means. Y

4. In a retractable ball pen, the combination defined in claim 1 and further characterized in that said plunger is formed at its forward end with a clutch shank for frictionally gripping the rear end of a ball point and reservoir unit and thereby causing said unit to move with said plunger with respect to said barrel housing.

References @ited in the le of this patent UNlTED STATES PATENTS 365,747 Hoffman June 28, 1887 2,580,754 Frentzel Jan. 1, 1952 2,624,315 Weisser et al. Ian. 6, 1953 FOREIGN PATENTS 809,514 Germany July 30, 1951 996,221 France Aug. 29, 1951 286,888 Switzerland Mar. 2, 1953 

